Do the 4.10's well worth it over 3.73's since you tow.

Also get it a limited slip. Like an Eaton etc... way better then the G80.

 

4.10s would place me at around 2500 RPM at my usual 80MPH cruising speed.. I of course wont be pulling a loaded trailer that fast But i was thinking about stepping down to 3.90s but for some reason i remember hearing in my NVH class at SIU that something about the cutting of that ratio makes them noisy, i know that is crazy sounding.. but i think i remember that.. anyone using 3.90s in their trucks? With that ratio i would be around 2250 at 80.. With the new engine in the truck and a good tune i think that i could easily pull the trailer with the Trans Am on it or the jeep (if that project ever gets going again..

In the mean time i just finished rebuilding the T5 in my El Camino again.. Just got that installed and filled up, got to put the top of the engine back together tomorrow evening, then wait for the machine shop where i work to get back to work on monday so that i can have them modify the idle tubes in the Qjet.. then reassemble that install it and hope to god that that fixes the damn thing and makes it idle properly with the 365 horse corvette cam..

WHEW..

Sounds like a lot...

 

I'd think long and hard about what gas mileage you're happy with before you go sticking 4.10s in. The best I can do on the highway now is 19.8 @ 60 mph (creeping like a slug), before with the 3.42s I was topping 23 mpg at 65 mph. Same everything, just the gear chance. The 4.10s make a really nice difference at WOT over the 3.42s. 3.73s are a nice midpoint between the two IMO.

 

GD.. I would kill to get 19.8, currently i get an average of 17.. that is unloaded, loaded i get around 10.. This 4.8 sucks gas.. I think the 5.3s get way better mileage.. That is why i dont feel so bad about upping the performance.. Cant make the mileage get much worse..

I have asked for the vette servo and the 4th gear super servo for xmas, think i may add the gears in there too.. I will admit that i will be unloaded most of the time but i think the gears will really help with around town fun.. i think that i will do all these mods first and build the engine over the winter and do the swap in the spring..

If these upgrades will help the 1-2 shift and make 4th gear hold stronger when pulling.. what can a man do for the poor 3rd gear, i bet he's feeling left out.. Think i may do a shift kit at the same time as swap as well as a Yank convertor set up for my combo (going to go with what they say)

 

that's 19 pure highway lol. I average around 13. The last tank I did some WOT stuff and managed 10 something.

17 mpg combined gas mileage is very good. If you go to 4.10s it will probably be 15 mpg combined. Trust me because I've been through it, the only way to get the seat of the pants in a 4600lb truck is to up the engine displacement. Save your money for a 6.0/6.2 and thank me later.

 

I am seriously concidering stroking the 5.7L Vette LS to a 383.. I am going to have to tear it all the way down to a block anyway to get the crank sent off for the reluctor to be changed.. I really feel that this would be a good combo for the truck.. a 6.3L stroked LS with a Tr220 cam and some ported heads, intake and a set of LTs.. Already has a CAI.. do a set of 3.90s and an eaton positraction unit in the rear axle and the vette servo and 4th gear holding servo convertor and shift kit.. Get it tuned by wait4meperformance and viola.. 14MPG but the fun factor would be well worth it..

 

I wouldn't waste money over the 3.90 vs 4:10 as they are so close. If your worried about MPG just go with 3.73's. Find 14bolt SF out of a V-max. You'll get a stronger axle and 3.73's or 4:10's plus its a bolt in swap.



I wouldn't waste money on stroking it either. Remove the crank, add all new bearings, change the reluctor wheel and be done . Spend the money on bad *** heads, Fast intake, and cam!!!! You would see more gained that way then just adding a more Ci's and stock heads and intake.

 

Ok, that actually sounds like a good deal on the rear axle.. I may look into that.. It would still be 6 lug right??

Ok and the LS1 thoughts were that i could stroke the short block.. Do some quick head work and intake work to get by.. and add better heads later if i chose to do so.. I just dont want to have to swing this engine more than once.. Like i said, cant really be without my truck for too long..

I think i could probably sell my dad the 8.6 out of my truck because his truck is currently a peg leg.. He has been wanting a different rear end for a while now..

 

Yeah six lug. And it will have disc brakes! Just make sure its for a GMT900 as that will be bolt-in. The 14b sf is used on the Vortec max and 6.2l trucks.

What castings heads do you have now???

 

truck has 243s on it and the LS1 has 853s.. Anyone know which is the better head? Going to build a seriously stout lower end.. and at least that way i only have to work on the top end at the worst..

Ideas on the top end for right now??

Thanks for the input..